Virus and Host Factors in HSV Cell-Cell Spread

描述（由申请人提供）：甲疱疹病毒病（单纯疱疹、水痘带状疱疹）的所有表现都是由于病毒能够从最初感染的细胞或粘膜表面的细胞扩散到该区域的其他细胞和支配初级复制部位的神经细胞。症状的复发和随之而来的病毒向新宿主的传播同样需要从感觉神经节细胞扩散到周围细胞和粘膜表面细胞之间的能力。令人惊讶的是，在复发性感染中，病毒的传播发生在适应性免疫反应中，包括应该中和从细胞释放的病毒的抗体反应。因此，这些病毒的致病特性取决于用于在细胞间传播的机制，这些机制保护病毒免受适应性免疫反应效应物的影响。人类甲疱疹病毒在宿主内的传播需要将新组装的病毒颗粒从其在高尔基体的组装位点运输到暴露的细胞表面，释放到细胞外介质或细胞连接处进行细胞间传播（CCS）。这两种贩运途径都没有得到很好的理解。在

DESCRIPTION (provided by applicant): All of the manifestations of alphaherpesvirus disease (herpes simplex, varicella zoster) result from the ability of the virus to spread from the initial infected cell or cells at mucosal surfaces to other cells in the area and to nerve cells that innervate the site of primary replication. Recurrence of symptoms and consequent spread of the virus to new hosts similarly requires the ability to spread from the sensory ganglion cells to cell at the periphery and among the cells on the mucosal surface. Amazingly, spread of the virus in recurrent infection occurs in the face of an adaptive immune response, including an antibody response that should neutralize virus released from the cell. The disease-causing properties of these viruses therefore depend on the mechanisms used for spread from cell to cell that protect the virus from exposure to effectors of the adaptive immune response. Spread of the human alphaherpesviruses within the host requires trafficking of newly assembled virus particles from their assembly site at the Golgi to exposed cell surfaces for release to extracellular medium or to cell junctions for cell-to-cell spread (CCS). Neither trafficking pathway is well understood. In part this is because, other than viral proteins required for entry of virus into host cells, no virl gene functions have been identified that are required for the process in most cell types. We have discovered that two viral gene products, pUL34 and pUL51, play critical roles in efficient virus release and/or CCS. Both proteins are apparently multifunctional. pUL34 is required for nuclear egress of herpesvirus capsids, and pUL51 has been shown to be required for efficient cytoplasmic assembly of the virus. We have discovered, however, that both proteins play critical roles in release and CCS that can be genetically uncoupled from their roles in virion assembly. Our overall goal is to test the hypothesis that HSV release and CCS are accomplished by viral hijacking of cellular pathways that sort host cell membrane proteins to appropriate surfaces and junctions. We will use two general approaches to this overall goal. The first approach (contained in the first two specific aims) is to characterize the functions and interactions of pUL34 and pUL51 that are required for virus release and CCS. These viral proteins can thus be used as tools to identify critical viral and cellular proteins that also participate. The second approach (contained in the third specific aim is to take advantage of recently developed information about the host pathways that deliver cellular membrane proteins to basolateral and junctional surfaces of cells and to probe those pathways using dominant negative inhibitors of critical molecules.